A DEADLY strain of fungus that occurs naturally in soil could replace pesticides in controlling worldwide crop pests, Welsh scientists have claimed.

A DEADLY strain of fungus that occurs naturally in soil could replace pesticides in controlling worldwide crop pests, Welsh scientists have claimed.

A team from Swansea University has identified a sustainable alternative to common chemicals used to control vine weevils and western flower thrips.

Professor Tariq Butt, from the School of Environment and Society, believes the development could help preserve the environment and dramatically reduce knock-on costs to farmers.

The project was funded by the Department for Environment, Food and Rural Affairs ( under the Horticulture LINK programme, the main government vehicle for sponsoring industry-academic applied research in horticulture.

Involving a variety of partners from different sectors, it focused on the problem of vine weevils and western flower thrips, insect pests that inflict millions of pounds of damage every year.

If approved, the new approach would significantly reduce the impact on human health, the environment and pesticide resistance.

The fungal biological control agent (BCA), called Metarhizium anisopliae, has shown highly successful results in horticultural tests. Whether applied as a drench or premixed into the growing medium, it gave excellent control of the vine weevil larvae and thrips pupae.

Prof Butt, who led the research at Swansea, said: “We concentrated our efforts on identifying a fungus that occurs naturally in soil, and that is a natural pathogen to the pests.

“The team discovered that a certain strain of the fungus, Metarhizium, is deadly to vine weevils and western flower thrips. Applying the fungus to the crop’s growing media, such as peat, coir or bark, we discovered that we could control the subterranean stages of these pests, and thus contribute significantly to the overall pest control strategy.

“The Metarhizium project needed a variety of partners from many different sectors and we were lucky to have help from Koppert Biological Systems, Bord Na Mona, Blue Xylem, the Horticultural Development Company, Symbio, Johnsons of Whixley, and W Godfrey and Sons who all had a great bearing on the success of our findings.

“Working with industrial partners meant we could see the real-life effects of the fungal- BCA. We also worked with Defland, Wallings and Bells Brothers Nurseries to test out our work.”

The team used Metarhizium combined with only 1% of a conventional chemical pesticide to achieve control comparable to the chemical when used at its full rate. Metarhizium has now been registered in Europe with Novozymes, the world leader in bio-innovations.

Hugh Frost, European agronomist at Novozymes, said: “The Novozymes BioAg business has been working with Swansea University to better understand the performance of the entomopathogenic fungus, Metarhizium anisopliae, and so develop products that can be registered for innovative, biological crop protection.

“Research is on-going and Novozymes is keen to investigate the further potential of this fungus in controlling other insects, in wider application, to assist growers in producing crops in an efficient, yet sustainable manner that meets their challenges of a decreasing portfolio of conventional pesticides.”

Dr Paul Sopp, of Fargro, a company that markets specialist horticultural products across the UK, described the potential of Metarhizium as a “significant step forward” in the control of both thrips and vine weevils.

For more information on the School of Environment and Society at Swansea University, visit www.swan.ac.uk/environment_society/

WalesOnline is part of Media Wales, publisher of the Western Mail, South Wales Echo, Wales on Sunday and the seven Celtic weekly titles, offering you unique access to our audience across Wales online and in print.